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Testing

Home water test kits compared: strips, mail-in and labs

Updated · Written from EPA, NSF, CDC and maker documents, each linked at the end · How we decide what to say

Short answer

For lead and PFAS, use a laboratory result, either a state-certified lab or a mail-in kit processed by a certified lab. Home strips are screening tools. Check which compounds the test covers and the lowest level it reports, especially for PFAS, where EPA's limits are 4 parts per trillion.

Start with what already exists

If you are on a public utility, it already tests your water. Read its report (how to read a CCR) and its page on this site before paying for a test. Public data cannot tell you about your own plumbing, which is why lead tests still make sense (why).

The four options

OptionGood forLimits
Utility data (CCR, EPA data)System-wide results for regulated contaminants and UCMR 5 PFASNot your tap; not your well
Home test strips or color kitsA quick screen, or checking that a treatment system is still working (EPA WaterSense)Not a laboratory analysis; do not use for a health decision
Mail-in laboratory kitsLead, PFAS and a panel of other contaminants without finding a lab yourselfCheck which lab processes it, which compounds it reports and the reporting limit
A state-certified lab, directlyPrivate wells, a specific concern, or when a certified lab is requiredFees and sampling rules vary; ask the lab

EPA says to use only laboratories certified to do drinking water testing, and lists state certification contacts so you can find one.

Which contaminants to test for

  • Private well, routine: EPA recommends annual testing for total coliform bacteria, nitrates, total dissolved solids and pH, and more often with small children, elderly adults or pregnancy in the home, or after flooding or changes near the well.
  • Lead: from your tap, with first-draw instructions (guide).
  • PFAS: a lab method that reports down to a low level. EPA’s UCMR 5 used Methods 533 and 537.1, and its minimum reporting levels for the 29 PFAS range from 2 to 20 ppt, so a lab whose reporting limit is much higher than 4 ppt cannot tell you whether you are under EPA’s PFOA and PFOS limits.

How to read a PFAS test

  1. Which compounds? Method 537.1 and Method 533 cover different lists of PFAS. HFPO-DA (GenX) is not in the 537.1 list, for example. Ask the lab.
  2. What reporting limit? Compare it to 4 ppt for PFOA and PFOS.
  3. Is it a screening test? A single sample is a snapshot. EPA’s compliance for utilities uses a running annual average.
  4. Who ran it? Ask whether the lab is certified for drinking water analysis in your state.

Be realistic

No home test replaces your utility’s regulatory monitoring. A test tells you what was in that sample, taken at that tap, at that time. If a result worries you, talk to your utility, your state drinking water program and, for health questions, a clinician.

Sources

Not medical or legal advice. This guide summarizes public documents so you can ask better questions of your utility, your health department or a certified lab. For health concerns, talk to a clinician; for compliance questions, to your state drinking water program. Pages on this site that name products may earn a commission, as disclosed on the affiliate disclosure page.